This assembly allows 3M Disc Pad Face Plate to be easily changed without removing the disc pad hub, allowing the operator to use a single tool for multiple applications from heavy grinding to finishing a workpiece.
Some face plates have ribbing on the bottom face. Ribbed face plates provide additional force when needed for optimal fracturing of the abrasive mineral. By reducing the area of contact, or pressure per square foot (PSI), ribbed face plates increase the grinding pressure of the abrasive with the same amount of operator effort, and extend disc life when dulling is a problem.
Choose a plate with the level of firmness needed for the application?a lighter density face plate for lighter weight grinding applications, and a harder density face plate for more heavyweight grinding applications. Using the correct face plate for the application ensures that the abrasive mineral will fracture as it should, maximizing the life of the abrasive. The plate comes in one of four different colors that indicate the density so the correct plate can be easily identified in the workroom: red = extra hard (for heavy grinding with the coarsest grades), black = hard (for heavy metal removal, large welds, etc.), gray = medium (for general purpose grinding and finishing), and white = soft (for finishing operations on flat or contoured surfaces).

Dynabrade 11476 Dynabelter Abrasive Belt Tool, Heavy-Duty
3M 22407, Roloc Disc 361F, 80 YF-weight, TR, 1-1/2 in, Die R150S, 7000045099
3M 05612, Polyurethane Glass Adhesive Sealant 590, Black, 600 mL Sausage Pack, 7000121536, 12/Case
3M 16066, PPS Mix Ratio Inserts, Mini (6 fl oz), 7000120511
3M 11412, Roloc Disc 361F, 36 YF-weight, TR, 1 in, Die R100N, 7000045092
3M 01326, PSA Cloth Disc 348D, P240 X-weight, 3 in x NH, Die 300V, 7000045069
3M 81728 Disc Pad Face Plate Ribbed, 9 in Extra Hard Red, 7000144145
Dynabrade 11486 Dynabelter Accu-Grinder Abrasive Belt Tool, Heavy-Duty
3M 76783, Cubitron II Hookit Cloth Disc 784F, 120+ XF-weight, 5 in x NH, Die 500X, 7100222757 
